PARIS
— When President Bush seeks Pope John Paul II's advice on Sunday on whether he should permit government funding of stem-cell research, Mr. Bush probably knows what he will hear. Roman Catholic authorities on both sides of the Atlantic have strongly opposed the idea.

But if he should raise the issue with fellow world leaders at the Group of Eight summit in Genoa, Italy, this weekend, they will give him a very different message.

European nations, in the midst of intense debate, are liberalizing their laws to allow, and even encourage, stem-cell research using human embryos so long as scientists abide by strict public controls of their work.

Stem cells can develop into specific cells such as skin cells, heart cells, and nerve cells. Scientists hope to use them one day to grow new human tissue to treat disorders including diabetes, Parkinson's disease, and spinal cord injuries. While stem cells are present in adults, scientists say the most versatile ones come from embryos a few days old.

The process of isolating embryonic stem cells results in the destruction of the embryo, however. Some opponents of the research say this amounts to taking a human life.

Unlike the United States - where publicly funded researchers are subject to government controls, but privately financed scientists can do pretty much what they like - European restrictions on research apply to everyone. And, although different countries have taken different approaches, they are united in their anxiety not to let scientists get ahead of public opinion.

The British approach

Britain is in the vanguard of European stem-cell research. A 1990 law allows scientists to use, create, and even clone embryos for therapeutic use.

Every research project, though, must be approved by the Human Fertilization and Embryology Authority (HFEA), which allows work only to combat infertility, congenital disease, and serious illness.

All embryos must be destroyed before they are 14 days old, when an embryonic nervous system appears in the form of what scientists call a "primitive streak."

The vast majority of such embryos come from so-called "surplus" stock at fertility clinics, which would normally be discarded. Although the law allows the creation of embryos through the fertilization of an egg with sperm, only 120 of the 50,000 embryos used for research over the past 11 years were artificially created, according to Hugh Whittall, deputy head of the HFEA.

"Not many women want to donate their eggs for research, so the material is not easy to get," he says.

And although British law also allows the cloning of embryos (so that the stem cells should be perfectly compatible with the donor's tissue), the authority has not yet issued any licenses to do so and has ruled out any reproductive cloning that would result in a human baby.

"Our framework has worked rather well," says Mr. Whittall. "The legislation is essentially permissive, but research happens in a controlled environment."

Other European countries, racing to bring their laws into line with recent breakthroughs in stem-cell research, are studying the British model. France, for example, where Parliament is currently revising the national bioethics law, is expected to adopt the broad outlines of the British pattern, though the government recently backed away from plans to permit the creation of embryos for research in the face of opposition from President Jacques Chirac.

Germany calls for moratorium

Nowhere has the public debate been as impassioned as in Germany, where Nazi experiments with eugenics have left people deeply sensitive about tinkering with nature, and where research on embryos is forbidden.

News that German scientists were working with imported stem cells caused an outcry two weeks ago, prompting the government to call for a voluntary moratorium on all such research until a newly formed National Ethics Council has studied the question and reported to parliament.

The debate has cut across political lines, pitting Chancellor Gerhard Schroder - who wants Germany to keep up with other countries on the cutting edge of scientific discovery - against the more cautious President Johannes Rau, for example.

The ethics council is under pressure to reach an opinion quickly. "We can no longer indefinitely postpone important decisions on gene technology," the council's chairman, law professor Spiros Simitis, told the Berlin daily Der Tagesspiegel last week. "We now have to set clear guidelines."

Other European countries such as Holland, Belgium, and Portugal are also drawing up new legislation.

"With the new developments in science and the new questions they raise, this is a highly topical issue for the public," says Sandrine Sabatier, an embryology specialist at the Council of Europe, which drafts human rights conventions for its 43 member states.

EU looks for consensus

The European Union, which funds scientific research, has also waded into the debate.

Its Group on Ethics and Science has recommended against funding experiments to clone embryos, which it calls "premature," and also opposes the creation of embryos for research purposes as "ethically unacceptable when spare embryos represent a ready available source" of stem cells.

But where embryo research is allowed to treat infertility, "it is hard to see any specific argument which would prohibit extending the scope of such research" to develop new treatments for severe illnesses, the group argued in a report last November.

National differences persist within the European Union, however. Some countries, such as Austria and Greece, have no law regulating embryo or stem-cell research.

Other nations, such as Norway and Italy, forbid research on embryos. And as the Council of Europe tries to draw up guidelines for embryo research, "the discussion is not leading us to a consensus," according to Ms. Sabatier.

Some scientists say they hope that the public debate raging across Europe will clarify matters. In Britain, for example, an amendment passed last December - broadening the 1990 law -was preceded by two years of public inquiries, wide media coverage, and lengthy parliamentary debate.

"A concerted effort to explain the science of what is going on had a significant impact on the outcome" of the vote, says Peter Collins, director of science policy at Britain's Royal Society, the equivalent of the US National Academy of Sciences.

Hilmar Stolter, a biologist at Hannover medical school in Germany, hopes for similar results in his country. "If we talk more openly about all this, in the long run the situation will be more stable," he predicts.

That situation could attract US scientists, if the mood in America turns against stem-cell research and public funding for it is denied.

Potential brain drain?

A leading US researcher, Roger Pedersen, announced last week that he was leaving the University of California in San Francisco for Cambridge University in England.

Whether Dr. Pedersen is the first drop in a reverse brain drain - as some US research groups have warned - remains to be seen. Scientists weigh many criteria when deciding where to live and work. But "the professional component of that decision will favor a location where you can get the most resources, the most challenging colleagues, and the opportunity to do what you want," points out Dr. Collins.

What he wants, within Britain's legal and ethical framework, that is. Dr. Pedersen will still have to earn a license from the HFEA to do his work. "And that is what we need - ethics coaching," says Professor Stolter. "This sort of research should not just happen. It should be authorized."